Within Australia there are three time zones: Eastern Standard Time (EST), Central Standard Time (CST, 30 minutes behind EST) and Western Standard Time (WST, two hours behind EST). South Australia and the Northern Territory operate on Central Standard Time. Daylight saving time operates in South Australia from the end of October to the end of March. During this time, clocks are wound back one hour. The time difference between Adelaide and a selection of countries is listed below (from March to October).
Country (and time difference in Adelaide)
East Coast (New York) - 13.5 hours
Central (Chicago) - 14.5 hours
Mountain (Denver) - 15.5 hours
Pacific (Los Angeles) - 16.5 hours | 
